Most vehicles currently feature conventional mechanical keys for access to the vehicle (unlocking and locking the doors) and turning on the engine, and which are normally associated with a door lock/release remote control. Recently, more advanced vehicle utilization systems, based on radio-frequency identification devices, have been proposed for use either in conjunction with or instead of conventional mechanical key systems. More specifically, such systems comprise a radio-frequency transmitter for transmitting an identification code, and an on-vehicle receiving unit which compares the incoming identification code with a code stored on the vehicle. In the event of a match, i.e. positive identification, the system releases the vehicle doors, and may also enable other vehicle functions, such as starting the engine, which may be done, for example, by pressing a button or turning an ignition knob.
The identification code may be stored in an electronic medium which may be combined with the radio-frequency transmitter to form an electronic key; and the electronic key may, for example, be in compact form, similar to a credit card, to be carried easily by the user. In the case of vehicle fleets, such as company cars, hire cars and similar, the same vehicle may be used by various users, each with a respective key. In this case, a table is stored on the vehicle containing a number of identification codes, each for enabling a respective electronic key to permit use of the vehicle.
Other data, besides the user identification code, is also known to be stored in the electronic key. For example, data relative to different authorization levels governing use of a given vehicle is known to be stored, so that the vehicle is only enabled, for example, for use during certain hours of the day, or for a limited mileage, or a limited number of days.
Another recent proposal is to store personal data in an electronic key, such as driver's seat, rearview mirror, car radio, or air conditioning settings, so that, by reading the personal data, the vehicle settings can be adjusted automatically in one operation.
All the above utilization systems are characterized by each key being assigned one identification code and related data. Consequently, the holder of an electronic key is only allowed access to a vehicle if the identification code of the electronic key is included in the code table stored on the vehicle. Conversely, to enable use of the vehicle, the user must be supplied with another electronic key whose identification code is stored in the on-vehicle code table. Consequently, though in possession of a personal electronic key containing personal data relative to on-vehicle device preferences or settings, the user is unable to take advantage of them by having to use another key.
Accordingly, there is a need in the art for a vehicle utilization system designed to eliminate the drawbacks of known systems.